mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-12-27 13:12:24 +02:00
836aa80368
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@14512 3c298f89-4303-0410-b956-a3cf2f4a3e73
74 lines
2.0 KiB
Diff
74 lines
2.0 KiB
Diff
Optionally omit the CS signal, if there's only one device on the bus.
|
|
|
|
--mb
|
|
|
|
|
|
|
|
--- a/drivers/spi/spi_gpio.c
|
|
+++ b/drivers/spi/spi_gpio.c
|
|
@@ -178,8 +178,10 @@ static void spi_gpio_chipselect(struct s
|
|
if (is_active)
|
|
setsck(spi, spi->mode & SPI_CPOL);
|
|
|
|
- /* SPI is normally active-low */
|
|
- gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
|
|
+ if (cs != SPI_GPIO_NO_CHIPSELECT) {
|
|
+ /* SPI is normally active-low */
|
|
+ gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
|
|
+ }
|
|
}
|
|
|
|
static int spi_gpio_setup(struct spi_device *spi)
|
|
@@ -191,15 +193,17 @@ static int spi_gpio_setup(struct spi_dev
|
|
return -EINVAL;
|
|
|
|
if (!spi->controller_state) {
|
|
- status = gpio_request(cs, spi->dev.bus_id);
|
|
- if (status)
|
|
- return status;
|
|
- status = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH);
|
|
+ if (cs != SPI_GPIO_NO_CHIPSELECT) {
|
|
+ status = gpio_request(cs, spi->dev.bus_id);
|
|
+ if (status)
|
|
+ return status;
|
|
+ status = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH);
|
|
+ }
|
|
}
|
|
if (!status)
|
|
status = spi_bitbang_setup(spi);
|
|
if (status) {
|
|
- if (!spi->controller_state)
|
|
+ if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT)
|
|
gpio_free(cs);
|
|
}
|
|
return status;
|
|
@@ -209,7 +213,8 @@ static void spi_gpio_cleanup(struct spi_
|
|
{
|
|
unsigned long cs = (unsigned long) spi->controller_data;
|
|
|
|
- gpio_free(cs);
|
|
+ if (cs != SPI_GPIO_NO_CHIPSELECT)
|
|
+ gpio_free(cs);
|
|
spi_bitbang_cleanup(spi);
|
|
}
|
|
|
|
--- a/include/linux/spi/spi_gpio.h
|
|
+++ b/include/linux/spi/spi_gpio.h
|
|
@@ -25,10 +25,16 @@
|
|
* ...
|
|
* };
|
|
*
|
|
+ * If chipselect is not used (there's only one device on the bus), assign
|
|
+ * SPI_GPIO_NO_CHIPSELECT to the controller_data:
|
|
+ * .controller_data = (void *) SPI_GPIO_NO_CHIPSELECT;
|
|
+ *
|
|
* If the bitbanged bus is later switched to a "native" controller,
|
|
* that platform_device and controller_data should be removed.
|
|
*/
|
|
|
|
+#define SPI_GPIO_NO_CHIPSELECT ((unsigned long)-1l)
|
|
+
|
|
/**
|
|
* struct spi_gpio_platform_data - parameter for bitbanged SPI master
|
|
* @sck: number of the GPIO used for clock output
|